I use the aerocoast EFB + cooler bag II. 4 day trip would include 3 dinners and depending on when the trip started/ended 2 to 4 lunches + snacks. It can hold everything I need cold EASILY for that kind of 4 day trip. Add an extra night for commuting, it's doable but things are getting tight now.

When we cook at home, which is most of the time, we generally have leftovers. If it's of the sort that freezes easily in Rubbermaid 2.9 cup container with little air, then it goes in one, gets labeled and set in the chest freezer for a trip. These will make up my dinners. We consider ourselves good cooks and I do generally look forward to these dinners all day when I'm working. This point is very important. If you don't want to eat it, you're going to eat out.

For lunch, I make up a salad in the same kind of containers, one for today if necessary, and one for tomorrow. Salad dressing in used baby food jars. For days after that it's sandwiches. I've seen guys make a full on sandwich in cockpit, pulling out a loaf of bread and packets of cheese and lunchmeat and such. I prefer to make mine in advance rather than try to make the cockpit my kitchen.

I always carry snacks in the cooler too and it depends on what we have when I'm packing. It can be carrots, oranges, boiled eggs, cheese sticks, and sometimes a banana for the first day. I also generally have peanutbutter crackers on hand.

In the roller back, I carry a packet or two of microwavable rice packets to go with a dinner or two if appropriate for that dinner as well as some crackers. Also carry sachets of oatmeal for those hotels that don't offer a free breakfast. I also keep some sardines (the more expensive ones really do taste good) with crackers as well as some individual salmon packs (taste so much better than tuna) as backup but I almost never need them... to the point of not really being necessary.

I stack the frozen dinners together on top of each other to reduce the surface area from touching non-frozen items and air. Next to them, I stack the refrigerated lunches. Two thin ice packs on the sides and one on the top. Cool snacks that I intend to eat that day go on the top.

If hotel fridge has no freezer, I stack the frozen dinners together in the fridge to reduce exposed surface area. I don't mind if they thaw over the course of the trip, as long as they stay cold enough to be safe (use common sense here and if you're really unsure about how common your sense is, you can buy a thermometer). I have felt the need to use the freezer in the crew room from time to time (after a night with a particularly week fridge) but not often and never had it stolen. Only time I've felt the need to throw something out it was due to the hotel fridge turning off with the light switch and I didn't realize it until the morning.

Empty tupperware is filled with ice before leaving the hotel and is stacked on bottom and top of frozen dinners.

I usually end up bringing some food back because I will eat out some too. I just don't want to beholden to eating out. After my last trip, I had an extra dinner that went back into the freezer, an extra lunch that I simply eat the day after I got back, and a couple oranges that went back into the household fruit bowl.

I have carried grilled meats in zip lock bags before as we grill a lot and in theory, this works really well as zip lock food takes up way less space than tupperware (though the tupperware I referenced does very will in the bag I referenced) but I'm just not a fan of reheated grilled meats so I found I tended to eat out more often when I was carrying those.

We actually don't use a crockpot in our cooking very often but I will say that about half of what I currently have stocked in our freezer for trip dinners are the type that work well in a crockpot. If you're looking to just make up a bunch of food at once for a trip rather than just taking bits of regular meals, this would be a good move.